Earthing switches are used for example in switch cabinets, where the electrical circuits that are under voltage must always be earthed before the door of the switch cabinet is opened.
Such switch cabinets may for example contain components of a converter for an electrical drive. Since the voltages used are ever increasing, it is necessary that the internal electrical insulation of the earthing switches is correspondingly improved with respect to flashovers and creeping currents.
Switches of the type in question are known for example from U.S. Pat. No. 2,331,632, from U.S. Pat. No. 2,009,815 and from U.S. Pat. No. 4,263,487.